3. X ray film is a photographic film
consisting of photographically
active or radiation-sensitive
4. DIRECT EXPOSURE FILMS : exposed to x- rays
only e.g.- dental film.
SCREEN FILMS : exposed to x-rays and light.
Film exposed to light only (fluorographic ,
duplicating films)
This is single emulsion film
6. Polyester made from polyethylene terephthlate
resin
THICKNESS OF FILM BASE
Medical x-ray : 0.18mm
Fluorographic roll film : 0.08mm
FUNCTION OF FILM BASE
Support for emulsion layer.
To transmit light so that an image can be viewed .
7. Transparent and uniform in transmitting light.
Strong but flexible.
Uniform in thickness.
Impermeable to water and processing solution
Dimensionally Stable throughout processing.
Inflammable
Chemically inactive
Uniform in colour
8. Mixture of gelatin solution + solvent of the film base.
Prevent separation of emulsion layer from the base
Without subbing layer , the emulsion swells and
contracts during the processing cycle
9. Consists of silver halide crystals suspended
in gelatin.
Thickness < 0.0005 inch.
Latent image will form in this layer .
Ingredients :
- Gelatin – Suspension medium
- Silver Halide - photosensitive
10. Photographic Gelatin - Cattle bone
Ideal suspension medium – keeps Silver Halide
grains well dispersed & prevents clumping
Processing solutions penetrate gelatin without
change in strength / performance
Easy availability
Uniform quality
11. Light sensitive material
Contains AgBr : 90 – 99%
AgI : 1 – 10%
Small crystals suspended in Gelatin
Crystal size : 1.0-1.5 microns with 6.3x109
grains per cubic centimeter of emulsion.
13. The grainoffer a larger surface area
to the imaging source , this increase
the filmsensitivityand speed
Added a lightabsorbingmagenta dye
to the surface of the grains ,known
as optical sensitizing dye
Advantages:
Greater sensitivityto light, increased
speed
Less cross-over effect
14. Thin layer of clear gelatin which is
applied to the emulsion .
functions
Protect the emulsion from light pressure
which might occur during use .
To provide suitable surface characteristics
15. Using only in single sided emulsion sheet film
Because the film emulsion layers swells during
processing
The film as a whole will have tendency to curl
To prevent this ,the emulsion layer is balanced by
coating the base on the opposite side to the
emulsion
16. HALATION : It is a phenomenon
characterised by formation of a diffuse
image or halo around the proper image.
This occurs mainly in the single sided
emulsion film.
17. Adding a dye to non- curl backing
Adding a dye to base.
18. • Preferred for single sided emulsion film.
• The dye colour selected is opposite or
complementary to exposing light.
• These dyes are removed during development.
Some times called as anti halo layer or gel
coat
19. Using in 35mm still and cine film
Dyes cannot be removed during development
20. Crossover is image degradation
caused by light produced in one
intensifying screen passing through
the film base and producing an image
in the opposite emulsion layer
21. It is a type of halation which occurs
when film is used with intensifying
screen.
Occurs only with double emulsion films
and two screens.
Coloured subbing layer is used.
Addition of magenta dye also reduces
cross over effect.
22. It is the sideway scattering of light within the
emulsion
This contributes to unsharpness (blurring) of image.
23. based on
- Single emulsion - Screen
type
- Double emulsion - Non
screen
TYPES OF X RAY FILMS
STRUCTURE
PRESENCE OF
SCREEN
25. 1. Direct- Exposure (non- screen type) film
Intra-oral dental film, kidney surgery film,
radiation monitoring film.
2. Screen-type film
(for use with intensifying screen)
26. • Screen-type film
• Photofluorographic film
• Cathod-ray-tube (CRT) photography : polaride film
• Duplication film
• Subtraction film
• Laser imaging film
27. Also known as non-screen film.
Some times know as enveloped- wrapped
exposure to x ray only
Thicker emulsion is used containing higher
concentration of silver halide.
Non-screen film is of low speed type.
A higher radiation dose is used.
28. PERI-APICAL- 31x41mm film(for single or
groups of teeth)
OCCLUSAL-57X76mm film(mandible or maxillae)
BITE-WING : similar to the periapical ,
positioned vertically behind the upper and lower
teeth .
Patent bite on the flap
Used to demonstrating crown
30. It enables radiographic exposure of kidney to
be made extra-abdominally during surgery for
stone removal.
Two film feature allows wider range of renal
stones to be demonstrated.
31. The film are enclosed in a light tight, water
proof polythene packet , the whole packet
is capable of being cold sterilized
The film can be processed in an automatic
processer
32. Similar to dental films in appearance.
On one side of the base is a high speed emulsion, whilst
on the other side is a slower emulsion
This permits a wide range of exposure level to be
recorded.
A large exposure to radiation may result in
complete blackening of the fast emulsion
33. It is the most widely used image receptor.
It is used in conjunction with pair of intensifying
screen.
Good screen film combination provide good quality
radiograph with high speed.
34. Screen type
Cassette fitted with a single intensifying
screen
Using in mammography
The films are medium to high contrast with
high definition, capable of demonstrating
micro calcification in soft tissue
36. Used in ultrasound imaging.
It is made up of positive and negative film sheets
with a pod of jellified processing chemistry.
37. Films should be protected from
Physical damage
Light
High temperature
High relative humidity
Harmful gases and fumes
X-rays and radioactive source
Fire
